Sheet material such as engineering drawings, blueprints, building and construction specifications, maps of different size, charts, and various other types of printed matter of relatively large dimension and area are often vertically filed. When such sheet material was vertically suspended in chambers formed by a cabinet construction, access to the interior of the chamber was usually made from one direction through a front opening of the cabinet. Structure for supporting the sheet material was located within the chamber and often comprised transverse front to back spaced support bars. In prior proposed cabinet constructions the sheet material included a suspension member on the top margin of the sheet material which cooperated with the spaced support bars in the cabinet for holding the sheet material in vertical relation. In such prior constructions, the configuration of the suspension member required tilting of the sheet material in its vertical plane to cooperably engage the spaced support members. Such tilting of the sheet material required vertical space to accommodate movement of corner portions of the sheet material during such tilting. When cabinet constructions were provided with support bars for tiers or upper and lower banks of supported sheet material, the space required to accommodate such tilting of the sheet material when inserted or withdrawn from the cabinet increased substantially the height of the cabinet. In some prior examples, the height of the cabinet might be increased as much as 6 inches for each tier, thus a two tiered cabinet would require an overall cabinet height of an additional 12 inches and a three tier an additional cabinet height of 18 inches or more.
In addition, in such prior proposed cabinet constructions for vertical filing when a plurality of sheets were clamped in a friction binder which was supported from spaced support bars, laterally outwardly splaying of the lower edge portions of the sheet material would make such tilting movement of the sheet material more difficult and would require the use of one hand in order to quide the clamped sheet material into place. Often when a plurality of sheets of material were clamped in a binder means, the weight of the sheet material on the binder might range from 20 to 30 pounds and thus the clamped sheet material became difficult and awkward to handle. The support bar means in the cabinet was often required to support as much as 750 pounds of sheet material and thus required a strong, sturdy support means which would not sag or bend at the center portion of the support bar means.
Prior proposed support construction for suspending vertical files utilizing spaced support points engaged through a top opening in a suspension member are shown in U.S. Pat. Nos. 3,165,104, 3,275,004, 3,208,457, and U.S. Pat. 2,990,961. In each of these examples of prior suspension of vertical files, a substantial tilting and some reciprocal horizontal movement of the upper margin of the sheet material was required in order to engage the spaced support points.
In some prior constructions, a single bar was employed for suspending vertical sheet material, such bars being cylindrical in cross section or polygonal in cross section. Such bars were engaged by side opening suspension members carried on the top margin of a sheet of material and while they would be engaged by substantially horizontal relative movement, vertical movement was provided in order to engage the bar in a notch or recess to restrain horizontal movement. In such prior constructions, the sheet material was required to be first lifted upwardly and then moved horizontally in order to disengage the support means. Thus, again, substantial vertical space was required for insertion or withdrawal of vertically disposed sheet material and in some instances some tilting movement was permitted.
The support bar means of the prior proposed cabinet constructions often did not provide for adjustable positioning of one or more vertically spaced support bar means which also permitted convenient ready disassembly and assembly of the support bar means with the cabinet construction. In some instances clip means have been used in a cabinet frame member for holding a support bar means, such clip means cooperating with vertically spaced openings in a cabinet frame member.